Regarding the assembly of motor vehicles, a configuration in which motor vehicles are assembled along one long straight-line shaped conveyor has widely been known conventionally. Specifically, a long straight-line shaped conveyor is arranged in a plant, and along this straight-line shaped conveyor, there are provided assembling stages for successively attaching parts to a vehicle being assembled along this conveyor; for example, an axle module is arranged at the first stage, a frame module is attached to the axle module at the next stage, the frame is turned over on the conveyor and an engine is attached to this frame at the next stage, and a cab is further attached to the frame at the next stage. This straight-line shaped conveyor moves in one direction as the assembling work progresses. At a position at which all of various assembling processes executed along this conveyor have been finished and a predetermined inspection has been completed, the assembled vehicle leaves the conveyor and is delivered.
Regarding this long straight-line shaped conveyor, there have been known a system in which the vehicle being assembled is moved at a fixed slow speed during the operation and a system in which the movement is stopped during the execution of assembling work and the vehicle is moved intermittently in accordance with set timing (tact).
At both sides of the straight-line shaped conveyor, stages for supplying parts and materials for assembly to the assembly line for vehicles are arranged. Specifically, the axle module, frame module, engine, cab etc. are supplied at positions necessary for the assembly line. The configuration is such that these parts and materials are prepared in a mode such as to be capable of being supplied, in principle, in the direction perpendicular to the flow direction of conveyor and are supplied to the conveyor. In the process in which parts and materials are supplied, in addition to work for supplying a member completed as a module onto the conveyor, work for conducting inspections before assembly, which are executed at the final assembling stage of each module and the like work are included.
Regarding the straight-line shaped conveyor of the conventional example, Patent Documents 1 to 3 (applicant: Honda Motor Co., Ltd.) described below have been known. Also, a conventionally known assembly line for vehicles that is not of a straight-line shape has disclosed in Patent Document 4 (applicant: MC Micro in Germany) described below. Also, though not for the assembly of vehicles, an example in which a manufacturing line is formed into a circular shape has been disclosed in Patent Document 5 (applicant: Ricoh Co., Ltd.) described below.    Patent Document 1: JP H10-59233 A    Patent Document 2: JP 2000-18251 A    Patent Document 3: JP 2002-79964 A    Patent Document 4: JP H8-290798 A    Patent Document 5: JP 2002-133710 A